/**
 * ***************************************************************************** Copyright (c) 2000,
 * 2011 IBM Corporation and others. All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0 which accompanies this
 * distribution, and is available at http://www.eclipse.org/legal/epl-v10.html
 *
 * <p>Contributors: IBM Corporation - initial API and implementation
 * *****************************************************************************
 */
package org.eclipse.jdt.internal.corext.refactoring.typeconstraints.types;

public final class ExtendsWildcardType extends WildcardType {

  protected ExtendsWildcardType(TypeEnvironment environment) {
    super(environment);
  }

  @Override
  public int getKind() {
    return EXTENDS_WILDCARD_TYPE;
  }

  @Override
  public TType getErasure() {
    return fBound.getErasure();
  }

  @Override
  public TType[] getSubTypes() {
    return new TType[] {fBound};
  }

  @Override
  protected boolean doCanAssignTo(TType lhs) {
    switch (lhs.getKind()) {
      case ARRAY_TYPE:
      case STANDARD_TYPE:
      case PARAMETERIZED_TYPE:
      case RAW_TYPE:
        return getBound().canAssignTo(lhs);

      case UNBOUND_WILDCARD_TYPE:
        return true;
      case SUPER_WILDCARD_TYPE:
      case EXTENDS_WILDCARD_TYPE:
        return ((WildcardType) lhs).checkAssignmentBound(getBound());

      case TYPE_VARIABLE:
        return ((TypeVariable) lhs).checkAssignmentBound(getBound());
      case CAPTURE_TYPE:
        return ((CaptureType) lhs).checkLowerBound(this);

      default:
        return false;
    }
  }

  @Override
  protected boolean checkTypeArgument(TType rhs) {
    switch (rhs.getKind()) {
      case ARRAY_TYPE:
      case STANDARD_TYPE:
      case PARAMETERIZED_TYPE:
        return rhs.canAssignTo(getBound());
      case RAW_TYPE:
        // unchecked conversion not allowed here; fix for
        // https://bugs.eclipse.org/bugs/show_bug.cgi?id=127583
        return !getBound().isParameterizedType() && rhs.canAssignTo(getBound());

      case UNBOUND_WILDCARD_TYPE:
        return getBound().isJavaLangObject();
      case EXTENDS_WILDCARD_TYPE:
        return ((ExtendsWildcardType) rhs).getBound().canAssignTo(getBound());
      case SUPER_WILDCARD_TYPE:
        return getBound().isJavaLangObject();

      case TYPE_VARIABLE:
        return rhs.canAssignTo(getBound());

      case CAPTURE_TYPE:
        return checkTypeArgument(((CaptureType) rhs).getWildcard());

      default:
        return false;
    }
  }

  @Override
  protected boolean checkAssignmentBound(TType rhs) {
    // ? extends Number is a set of all subtyes of number and number.
    // so the only thing that can be assigned is null since null is
    // a sub type of everything
    return rhs.isNullType();
  }

  @Override
  public String getName() {
    return internalGetName("extends"); // $NON-NLS-1$
  }

  @Override
  protected String getPlainPrettySignature() {
    return internalGetPrettySignature("extends"); // $NON-NLS-1$
  }
}
